The present invention relates to a printing apparatus. More specifically, the present invention relates to a printing apparatus wherein a setting means and a controlling means of the amount of feed of a relative movement between a printing medium and a printing mechanism such as line feeding of the printing media and pitch feeding of a printing head.
Generally, in printing apparatuses such as electronic typewriters, when printing writings over a plurality of lines, a format of setting the right margin and the left margin, the amount of line feeding in changing the line and the like is determined before printing.
In the conventional electronic typewriter, the unit amount of line feeding of the paper is determined normally at 1/6 inch, and a configuration is made in a manner that four kinds of amounts of line feeding, 1, 11/2, 2 or 3 times the unit amount of line feed can be set selectively by operating a line key.
Also, for the user requiring an amount of line feeding other than the 1/6 inch unit amount, an electronic typewriter of special specifications is provided wherein paper can be
fed by a special unit amount, for example, 1/8 inch or 9/48 inch by changing the gear ratio by means of replacing an intermediate gear installed in a paper feeding mechanism.
In this type of electronic typewriter, when an amount of line feeding other than the 1/6 inch unit amount is required, the unit amount of feed can be changed to a special one by changing the gear ratio, but the general users cannot change the unit amount of feed freely as required, and the unit amount of line feeding is limited to 1/6 inch or 1.5, 2 or 3 times thereof, this being a problem remaining unsolved.
Therefore, the principal object of the present invention is to provide a printing apparatus wherein the amount of feed for moving relatively the printing media and the printing mechanism can be set by selecting any one from among a plurality of unit amounts of feed and by selecting any one from among coefficients to multiply the unit amount of feed.